Poly[dimethyl-ammonium [aquadi-μ(2)-oxalato-samarate(III)] trihydrate].

In the title complex, {(C(2)H(8)N)[Sm(C(2)O(4))(2)(H(2)O)]·3H(2)O}(n), the Sm(III) atom is chelated by four oxalate ligands and one water mol-ecule forming a distorted tricapped trigonal-prismatic geometry. Each oxalate ligand chelates to two Sm(III) atoms, generating a three-dimensional anionic network with cavities in which the ammonium cations and lattice water mol-ecules reside. Various O-H⋯O, N-H⋯O and C-H⋯O hydrogen-bonding inter-actions further stablize the crystal structure.